From U.S. Pat. No. 5,987,883, a method and an arrangement are known wherein an interruption of the diagnosis of the catalytic converter is provided when specific stop criteria are present. One stop criterion is the reaching of a threshold value of the charge of oxygen into the catalytic converter or of the discharge of oxygen out of the catalytic converter. The limiting of the diagnosis considers nonlinearities in the oxygen storage behavior of the catalytic converter. The oxygen storage in the catalytic converter for high oxygen charge or oxygen discharge cannot be described by the same model parameters as for low oxygen charge or oxygen discharge.
The interruption or the non-triggering of the diagnosis under such conditions, on the one hand, reliably prevents false diagnostic results but, on the other hand, reduces also the rate of diagnosis.